The municipality of Rus (3,807 inhabitants in 2007: 4,630 ha; municipal website) is located 50 km north-east of Jaén.

Most probably settled by the Phoenicians, subsequently fortified by the Iberians, the region of Rus was settled by several Roman villae (estates) that formed the Republica Ruradensium. The Visigoths built an oratory in the rocks of Valdecanales; the only hypogea kept in southern Spain, the sanctuary was proclaimed a National Monument on 21 March 1970. Following the Moorish conquest in 713, religious persecution against the Christians was ordered by Abderram‡n II; sacked and burned in 852, the hypogea was probably then used by the Mozarabs as a secrete place of worship. The Moors renamed the antique Ruradia Rus-al-Jabel and developed agriculture, building mills. They built at that time a triangular fortress, of which only one tower has remained. The town was mostly used as a camp during the wars between the Christians and the Moors; it could house several thousands soldiers and riders.
After the Christian reconquest, Rus was mentioned for the first time in 1280 in a document signed by knights Martín Fernández de Rus and Martín Pérez de Rus. In 1628, King Philip IV granted the title of villa (town) to Rus, which became independent of Baeza. The neighbouring village of El Marmól was incorporated to Rus in 1886; the villagers asked for secession in 1922 but the Provincial Court declared in 1927 El Marmól a submunicipal entity.

The flag of Rus, adopted on 28 December 2007 by the Municipal Council and submitted on 2 January 2008 to the Directorate General of the Local Administration, is prescribed by a Resolution adopted on 15 January 2008 by the Directorate General of the Local Administration and published on 29 January 2008 in the official gazette of Andalusia, No. 20, pp. 30-31 (text).
The flag is described as follows:

Flag: Rectangular flag, with the length one and a half the height, yellow (or) with a bend sable (black) of 1/5th of the hoist size. Centered and over the bend, the municipal coat of arms with a height equal to 1/2 of the flag's hoist.

The coat of arms of Rus is prescribed by Royal Decree No. 2,884 adopted on 28 October 1977 and published on 19 November 1977 in the Spanish official gazette, No. 277, p. 25,380 (text). This was confirmed by a Resolution adopted on 30 November 2004 by the Directorate General of the Local Administration and published on 20 December 2004 in the official gazette of Andalusia, No. 246, pp. 28,986-29,002 (text).
The coat of arms, validated by the Royal Academy of History, is described as follows:

Coat of arms: Or a bend sable engulfed by dragons vert, a bordure gules inscribed in chief with the writing "R. P. RVRADENSIVM" in letters or. The shield surmounted by a Royal crown closed.

The black bend engulfed by the dragons recalls that Alvar Sánchez de Rus was made knight and granted arms by King Alfonso IX after the Battle of Salado; they represent honour, loyalty and bravery. The red bordure highlights the strong temper of the men and women of Rus, who shed their blood several times for their land. The writing recalls the Roman past of the town.
[Símbolos de las Entidades Locales de Andalucía. Jaén (PDF file)]

The Royal Academy validated the proposed arms, although the use of a bordure for such as shield "appears neither appropriate nor usual". The designers of the arms claimed that the bordure charged with the Latin writing reflects the antiquity of the Council of Rus and are derived from a marble pedestal dedicated to Emperor Aurelian.
[Boletín de la Real Academia de la Historia, 1980, 187, 1: 792]

The submunicipal entity of El Mármol (211 inhabitants in 2013) is located 5 km of Rus and 60 km of Jaén.

El Mármol was probably during the Muslim period a small estate protected by a fortified tower, replaced in the 13th century by a Christian tower. After the Christian reconquest, the village was granted in 1233 by King Ferdinand III the Saint to Friar Domingo de Soria, first bishop of the re-established Diocese of Baeza, as a reward for his support during the reconquest. In 1249, El Mármol was granted the status of villa, transferred to the Bishop of Jaén, while all the surrounding villages (Canena, Rus, Begíjar, Lupíon etc.) were ruled by the Council of Baeza.
El Mármol was acquired in 1577 by Juan Vázquez de Salazar y Molina, Philip II's secretary. Incorporated for a while to the Marquisate of Mancera in the 17th century, El Mármol was transferred back to the Vázquez de Salazar y Molina, who ruled it until the suppression of the feudal system.
Due to bad management by its next owner, the Marquis of Camarasa, El Mármol got bankrupted; the debt was paid by the town of Rus, which incorporated El Mármol in 1886.
[Jaén desde mi atalaya, 16 March 2011]

The flag (photo) and arms of El Mármol were approved by administrative silence [that is, the administration in charge failed to assess the proposed symbols in due time], as confirmed by a Resolution adopted on 30 November 2004 by the Directorate General of the Local Administration and published on 20 December 2004 in the official gazette of Andalusia, No. 246, pp. 28,986-29,002 (text).
The symbols are described as follows (unofficial website):

Flag: Rectangular, in proportions 11 x 18, made of three parallel stripes perpendicular to the hoist. The colour distribution shall be as follows: the first and third fourths of the hoist, red, the second, central of one half, green. Centered, at the closest third of hoist, the coat of arms of the submunicipal entity.Coat of arms: Per pale, 1. Gules a tower or port and windows azure masoned sable ensigned by a bishop's mitre or with infulae of the same, 2. Argent a dark Christ clad gules and argent on double horizontal waves azure truncated on both sides. The shield in Spanish shape and surmounted by a Royal Spanish crown.

The coat of arms features the village's patron saint, the Christ of the Waters (Cristo de las Aguas), celebrated the second Sunday of September. The statue is kept in a lateral chapel of the church of Our Lady of Peace (16th century).